Following advancements in information security techniques such as cryptology techniques and digital signature techniques, progress has been made in research and development to make electronic money a viable substitute for currency, and such electronic money is already in actual use to some extent.
Patent Document 1 discloses a technique that aims to realize safe circulation of electronic money deposited in an IC card. With an object of performing online transfer of electronic money from an electronic purse to an IC card and from a bank account to the electronic purse while ensuring high reliability, this document discloses a technique for transferring from an account at a financial institution to an electronic purse, and transferring electronic money from the electronic purse to an IC card inserted in the electronic purse. Here, after the IC card which has had the electronic money deposited therein is removed from the electronic purse, the balance of the IC card is automatically extinguished therefrom if account settlement using the electronic money is not performed within a certain length of time.
Patent Document 2 discloses a theft prevention system that, with a simple structure, enables a location of a theft prevention target object that has been stolen or lost to be specified. This is realized by mounting a wireless communication device in the theft prevention target object. The wireless communication device conforms to a communication format of a simple mobile phone system, and transmits its own terminal identification number with a predetermined timing. The location of the theft prevention target object is managed by managing the location of the wireless communication device based on the terminal identification number received from the wireless communication device and a base station identification number of a base station that received the terminal identification number.
Patent Document 1: Japanese Patent Application Publication No. 2004-139604
Patent Document 2: Japanese Patent Application Publication No. H09-128663